Field
The described technology generally relates to a battery pack and a method of controlling the same.
Description of the Related Technology
Secondary batteries have favorable characteristics such as high energy density and are being applied to portable devices as well as electric vehicles (EVs), hybrid vehicles (HVs), and the like, which are driven by an electrical driving source.
Due to environmental and resource concerns, demand for a system that can store power and effectively utilize the stored power has increased. In turn, secondary batteries have emerged as a novel energy source as being environmentally friendly and enhancing energy efficiency, since less harmful byproducts are generated as well as the use of fossil fuel reduced.
A plurality of battery cells are generally connected in series and/or parallel to form a battery module, and a plurality of battery modules are connected in series and/or parallel to form a battery pack generally applied to electric vehicles. Each cell includes a positive electrode current collector, a separator, an active material, an electrolyte, and an aluminum thin film layer so that charging and discharging can be performed by an electrochemical reaction between the components.
Typically, the battery pack further includes a battery management system (BMS) for monitoring and controlling a state of the secondary batteries by applying an algorithm for controlling power supply with respect to a driving load such as a motor measuring electrical characteristics values, which can include a current or a voltage that controls charging and discharging, controlling voltage equalization, and estimating a state of charge (SOC).
A multi-module battery pack can have various forms according to the circuitry or printed circuit board (PCB) configurations. In order to enhance the battery pack's efficiency, a multi-slave structure including a plurality of BMS′ including a master or main BMS controlling a plurality of slave BMS′ is largely used.
In such a structure, in order to check the current battery state and utilize the same for controlling charging and discharging the batteries, the master BMS communicates with the slave BMS′ to collect data regarding a plurality of batteries handled by the slave BMS′.